A scroll saw includes upper and lower driving arms, a saw blade, a blade retaining unit, push rod, a biasing unit, and an actuating unit. The blade retaining unit includes a pivot seat mounted pivotally on a distal end of the upper driving arm, and an upper blade holder mounted on the pivot seat. The pivot seat is pivotable relative to the upper driving arm from a first position, where the upper blade holder engages an upper blade end of the saw blade, to a second position, where the upper blade holder disengages from the upper blade end. The biasing unit provides a biasing force that pivots the pivot seat to the first position. The actuating unit provides a pressing force on the push rod to push the pivot seat to pivot to the second position so as to permit release of the saw blade.
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1. A scroll saw comprising:
upper and lower driving arms, each of which has a distal end; a saw blade having upper and lower blade ends; a blade retaining unit including a lower blade holder mounted on said distal end of said lower driving arm to hold removably said lower blade end, a pivot seat mounted pivotally on said distal end of said upper driving arm, and an upper blade holder mounted on said pivot seat, said pivot seat being pivotable relative to said upper driving arm from a first position, where said upper blade holder engages said upper blade end, to a second position, where said upper blade holder disengages from said upper blade end; a push rod having a connecting end coupled to said pivot seat, and a pressing end opposite to said connecting end; a biasing unit for providing a biasing force that enables said pivot seat to pivot to the first position; and an actuating unit operable so as to provide a pressing force on said pressing end of said push rod for enabling said push rod to push said pivot seat to pivot to the second position against biasing action of said biasing unit so as to permit release of said saw blade from said upper and lower blade holders.
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3. The scroll saw as claimed in
4. The scroll saw as claimed in
5. The scroll saw as claimed in
a link member mounted pivotally in said upper frame portion, and having an upper link end abutting against said pressing end of said push rod, and a lower link end, an eccentric cam wheel mounted rotatably in said upper frame portion and abutting against said lower link end, and a lever coupled to said cam wheel and accessible from an exterior of said upper frame portion so as to drive rotation of said cam wheel.
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7. The scroll saw as claimed in
8. The scroll saw as claimed in
9. The scroll saw as claimed in
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This application claims priority of Taiwanese application no. 092202516, filed on Feb. 18, 2003.
1. Field of the Invention
The invention relates to a scroll saw, more particularly to a scroll saw with a saw blade that is easy to replace.
2. Description of the Related Art
Referring to
In use, when the rotary knob 14 is rotated to move the shank 13 upwardly, the upper blade holder 16 will move accordingly for increasing the tension of the saw blade 18 and for preventing removal of the saw blade 18 from the upper and lower blade holders 16, 17. On the other hand, when the rotary knob 14 is rotated to move the shank 13 downwardly, the saw blade 18 can be removed from the upper and lower blade holders 16, 17 for replacement purposes.
The following are some of the drawbacks of the aforesaid conventional scroll saw 1:
1. Quick attachment or removal of the saw blade 18 is not possible because of the need to rotate the rotary knob 14 before the upper blade holder 16 can be moved to engage or disengage from the upper end portion 181 of the saw blade 18.
2. Proper adjustment of the blade tension cannot be conveniently conducted due to the threaded engagement between the shank 13 and the rotary knob 14. When the tension of the saw blade 18 is too high, the saw blade 18 tends to break easily. On the other hand, when the tension of the saw blade 18 is too low, the saw blade 18 tends to wobble during a cutting operation.
Therefore, the object of the present invention is to provide a scroll saw that can overcome the aforesaid drawbacks associated with the prior art.
Accordingly, a scroll saw of this invention comprises:
upper and lower driving arms, each of which has a distal end;
a saw blade having upper and lower blade ends;
a blade retaining unit including a lower blade holder mounted on the distal end of the lower driving arm to hold removably the lower blade end, a pivot seat mounted pivotally on the distal end of the upper driving arm, and an upper blade holder mounted on the pivot seat, the pivot seat being pivotable relative to the upper driving arm from a first position, where the upper blade holder engages the upper blade end, to a second position, where the upper blade holder disengages from the upper blade end;
a push rod having a connecting end coupled to the pivot seat, and a pressing end opposite to the connecting end;
a biasing unit for providing a biasing force that enables the pivot seat to pivot to the first position; and
an actuating unit operable so as to provide a pressing force on the pressing end of the push rod for enabling the push rod to push the pivot seat to pivot to the second position against biasing action of the biasing unit so as to permit release of the saw blade from the upper and lower blade holders.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Referring to
The saw frame 2 is generally C-shaped and has hollow upper and lower frame portions 21, 22. Each of the upper and lower frame portions 21, 22 has upper and lower driving arms 31, 32 mounted pivotally and respectively therein in a conventional manner. Each of the upper and lower driving arms 31, 32 has a respective distal end 311, 321.
The saw blade 4 extends between the upper and lower driving arms 31, 32, and has upper and lower blade ends 41, 42.
The blade retaining unit includes a lower blade holder 35 mounted fixedly on the distal end 321 of the lower driving arm 32 to hold removably the lower blade end 42, a pivot seat 33 mounted pivotally on the distal end 311 of the upper driving arm 31, and an upper blade holder 34 mounted on the pivot seat 33. The pivot seat 33 includes an upper seat section 332, a lower seat section 333 connected to the upper blade holder 34, and an elbow section 331 that connects the upper and lower seat sections 332, 333, and that is mounted pivotally on the distal end 311 of the upper driving arm 31. The pivot seat 33 is pivotable relative to the upper driving arm 31 from a first position, where the upper blade holder 34 engages the upper blade end 41 (see FIGS. 2 and 3), to a second position, where the upper blade holder 34 disengages from the upper blade end 41 (see FIGS. 4 and 5).
The upper driving arm 31 further has a guide block 36 secured on a top side 312 thereof. The guide block 36 is formed with a through hole 361 that permits the push rod 5 to extend slidably through the guide block 36. The upper seat section 332 of the pivot seat 33 is formed with a threaded hole 334 parallel to the upper driving arm 31. The push rod 5 has a connecting end 51 and an opposite pressing end 52. The connecting end 51 of the push rod 5 is connected threadedly to the upper seat section 332 of the pivot seat 33 in the threaded hole 334.
The actuating unit 6 includes a link member 61, an eccentric cam wheel 62, and a lever 63. The link member 61 is mounted pivotally in the upper frame portion 21, and has an upper link end 611 abutting against the pressing end 52 of the push rod 5, and a lower link end 612. The eccentric cam wheel 62 is mounted rotatably in the upper frame portion 21, and abuts against the lower link end 612. The lever 63 includes a connecting section 631 coupled to the cam wheel 62, and a handle section 632 accessible from an exterior of the upper frame portion 21 so as to drive rotation of the cam wheel 62.
The biasing unit 7 includes a first spring member 71 and a second spring member 72. The first spring member 71 is sleeved on the push rod 5, and has a first end abutting against the guide block 36 and a second end abutting against the pressing end 52 of the push rod 5. The second spring member 72 is also sleeved on the push rod 51, and has a first end abutting against the guide block 36 and a second end abutting against the upper link end 611 of the link member 61. In this embodiment, the first and second spring members 71, 72 are coiled compression springs that coil in opposite directions, and the second spring member 72 winds around the first spring member 71.
Referring to
Referring again to
Referring to
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
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